I have a patch for this here: https://github.com/php/php-src/pull/144
If you could test whether it fixes the issue for you it would help a lot.
We had some issues reproducing the problem consistently, so would be nice to verify this :)

This bug has been fixed in SVN.
Snapshots of the sources are packaged every three hours; this change
will be in the next snapshot. You can grab the snapshot at
http://snaps.php.net/.
For Windows:
http://windows.php.net/snapshots/
Thank you for the report, and for helping us make PHP better.
the reason why jpauli and I can not reproduce is (it's silly):
I typo "USE_ZEND_ALLOC *&&* valgrind" at the first time, then I always ctrl+r
and jpauli copied my command from the pastbin :)
thanks